Alan Stevens had the idea for an audio series loosely based on a film called Yojimbo by Akira Kurosawa. The film is about a Samurai who plays two powerful families off against one another in order to benefit himself.

Around this time, BBC Books published a Doctor Who novel titled Corpse Marker as part of its line of Past Doctor Adventures. Written by Chris Boucher it served as a sequel to his 1977 Doctor Who story The Robots of Death and was also a crossover with the BBC television series Blake's 7 due to the inclusion of Carnell, a character originating in that series. Stevens contacted Boucher and proposed the idea of an audio drama using the setting established in Corpse Marker named Kaldor City. Boucher encouraged Stevens to write the script, which he wrote in collaboration with Jim Smith. Pleased with the results, Boucher gave his full approval to proceed with the concept.[1]

Stevens initially approached BBV, an audio and video production company specialising in Doctor Who related productions, with the script but showed little interest in the idea. Big Finish, a prodcution company licensed by the BBC to produce Doctor Who audio drama, were also approached. Ultimately, Stevens decided to produce it himself and so set up a company called Magic Bullet.

In assembling the key players, Stevens hired sound designer Alistair Lock whom he previously worked with on a series of Blake's 7 audio productions; Travis: The Final Act, The Mark of Kane, and The Logic of Empire. Stevens created the character of Kaston Iago specifically for Paul Darrow, best known for the role of 'Kerr Avon' in Blake's 7. Alexis Kanner from the ITC television series The Prisoner was also considered for the role should Darrow prove unavailable.

Using his casting connections from the Blake's 7 audios, Stevens approached Darrow who agreed to play the role. Series regulars Trevor Cooper, Brian Croucher and Peter Miles were also known to Stevens from the same audio productions. Russell Hunter was contacted through a friend of Stevens and agreed to reprise the role of Uvanov from The Robots of Death. Scott Fredericks who originally played the role of Carnell in the Blake's 7 episode Weapon proved more difficult to track down due to residing in Ireland. Stevens eventually got in touch through BBC Residuals, who kindly forwarded a copy of the script. Stevens later recalled: "I'd written a script with Carnell in before I'd even contacted the actor. It would have been a terrible mess if he'd decided not to do it."[2]

The character of Kaston Iago, who is repeatedly hinted to be the Blake's 7 protagonist Kerr Avon, is named after the manipulative character of the same name from Shakespeare's Othello and the noted Shakespeare editor David Kastan.

The series is notable for its lack of incidental music instead relying almost solely on a diegetic soundscape to create the atmosphere. The theme tune, composed by Alistair Lock, is roughly based on 'Avon's theme', which he previously used in the unofficial Blake's 7 audio The Logic of Empire.

The Prisoner is a twenty minute play released as part of an MJTV Productions CD, The Actor Speaks: Paul Darrow, which featured an interview and several short stories unrelated to the series.

Kaldor City was written as a six-part audio series. Since the release of Storm Mine there have been four attempts to develop a new 'Kaldor City' story by established Doctor Who and/or spinoff writers, none of which have, to date, managed to progress beyond the draft stage. Series producer Alan Stevens maintains, "If there's an interesting enough idea out there, the series will continue, but at the moment we're waiting for that idea to come along.[3]In fact, Fiona and I even wrote Kaldor City 7 ourselves, and then threw it away, because it just proved to us that the series had come to a natural end with Storm Mine."[4]